First Online: 29 September 2011Received: 24 June 2011Revised: 17 August 2011Accepted: 29 September 2011

Abstract

IntroductionProne position is known to improve oxygenation in patients with acute lung injury ALI and the acute respiratory distress syndrome ARDS. Supine upright semirecumbent position also exerts beneficial effects on gas exchange in this group of patients. We evaluated the effect of combining upright and prone position on oxygenation and respiratory mechanics in patients with ALI or ARDS in a prospective randomized cross-over study.

MethodsAfter turning them prone from a supine position, we randomized the patients to a prone position or combined prone and upright position. After 2 hours, the position was changed to the other one for another 6 hours. The gas exchange and static compliance of the respiratory system, lungs, and chest wall were assessed in the supine position as well as every hour in the prone position.

ResultsTwenty patients were enrolled in the study. The PaO2-FiO2 ratio improved significantly from the supine to the prone position and further significantly increased with additional upright position. Fourteen 70% patients were classified as responders to the prone position, whereas 17 85% patients responded to the prone plus upright position compared with the supine position P = n.s

No statistically significant changes were found with respect to compliance.

ConclusionsCombining the prone position with the upright position in patients with ALI or ARDS leads to further improvement of oxygenation.

Trial registrationClinical Trials No. NCT00753129

AbbreviationsALIacute lung injury

ARDSacute respiratory distress syndrome

Ccwcompliance chest wall

Cpulmcompliance lung

Ctotcompliance total

ECGelectrocardiography

ICUintensive care unit

IQRinterquartile range

LISlung injury score

MVmechanical ventilation

PPprone position

SAPS IIsimplified acute physiology score

PIPpeak inspiratory pressure

UPupright position.

Electronic supplementary materialThe online version of this article doi:10.1186-cc10471 contains supplementary material, which is available to authorized users.